In a wireless communications system such as a long term evolution (LTE) system, feedback information for downlink data (i.e., ACK information indicating that the downlink data is correctly received or NACK information indicating that the downlink data is not correctly received) that is sent by a user equipment (UE) to an evolved base station (e.g., Evolved NodeB, eNB) is borne by a physical uplink control channel (PUCCH). In a machine type communications (MTC) application with a large number of terminals, multiple terminals can be integrated into a scheduling group. Abase station can schedule one or more terminals in a scheduling group through downlink control information (DCI) used for downlink data group scheduling, and the scheduled terminal can receive the downlink data according to the DCI and then send the feedback information for the downlink data to the base station through the PUCCH, where the DCI is borne by a physical downlink control channel (PDCCH). A PUCCH resource used by the scheduled terminal (i.e., a resource mapped by the PUCCH used by the terminal) is related to a PDCCH resource used by the base station (i.e., a control channel element (CCE) mapped by the PDCCH used by the base station), and is referred to as an implicit feedback resource.
However, in the prior art, the number of terminals scheduled by the base station is restricted by an aggregation level adopted by the PDCCH which is used by the base station to bear the DCI, and if the number of terminals scheduled by the base station exceeds the aggregation level adopted by the PDCCH, some terminals cannot send feedback information for downlink data to the base station due to lack of the PUCCH resource, which degrades feedback capabilities of the terminals.